Wire strain reliever



Jun 8, 1954 T. c. SMITH 2,680,776

WIRE STRAIN RELIEVER Filed Sept. 29, 1952 Patented June 8, 1954 UNITED STATES PATENT OFFICE WIRE STRAIN RELIEVER Theodore C. Smith, Drexel Hill, Pa.

Application September 29, 1952, Serial No. 311,997

7 Claims. 1

My invention relates to a new and useful wire strain reliever and has for one of itsv objects to produce an exceedingly simple and relatively inexpensive article of this character which is strong, durable and highly efficient in operation.

Another object of the invention is to produce a wire strain reliever comprised of two identical members to be co-operatively employed in reverse and inverted relationship collectively defining an article which will securely lock and hold an electrical conductor, cable or wire against endwise movement thereof in a mounting, support or plate provided to receive the strain reliever.

Another object of this invention is to provide indicia on one end of each member to indicate to the party assembling the device for use when the members are in proper co-operative relation to each other.

Another object of the present invention is to produce a wire strain reliever comprising identical companion members mounted in reverse and inverted. relationship, said. members capable of being formed in a single mold or a multiple cavity mold in which all cavities are identical thereby reducing the cost of manufacture and minimizing the packing and assembling operations because of the duplicate configuration of the companion members.

A further object of the invention is to produce a wire strain reliever so constructed that oppositely projecting kinks or bends are formed in a conductor when the two members of the article are disposed in opposed relation on the conductor and pressed towards each other as when mounted inanopening in a panel or other support.

A still further object of the present invention is to produce a wire strain reliever consisting of two identical members assembled in reverse and inverted relationship, each member comprised of a semi-cylindrical body of insulating material having a longitudinal channel which is a true semi-circle in cross section and with which, adjacent one end thereof, communicates an internal bay or recess of semi-elliptical form, said channel having a rib projecting part way thereinto v adjacent the other end and each member having a semi-elliptical exterior groove midway the ends thereof, the rib of one member being positioned opposite the bay or recess of the companion member when the two members are assembled in reverse and inverted relationship to produce two bends, in opposite directions, in a cable or conductor located between said members thereby firmly gripping said cableor conductor to relieve any strain on aterminal should-the cable or conductor be pulledlongitudinally.

With the above. and other objects in view this invention consists of the details of construction and. combination of elements hereinafter set forthand then designated by the claims; I

.In: order that those skilled in the art to-which this invention appertains may understand. how to make and use the same I will describe its construction in detail referring by numerals to the accompanying drawing forming a part hereof, in which:

Fig. l is a longitudinal sectional view of the wire strain reliever constructed in accordance with my invention and shown in assembled relation in a mounting member or panel and a cable, in phantom, betweenthem.

Fig. 2 is a cross section on the line 2'--2 of Fig. 1 of the wire strain reliever per se.

Fig. 3 is a similar section on the line 3'--3' of Fi 1.

Fig. 4 is an end view of said wire strain'reliever.

Fig. 5 is a longitudinal section of the two members both turned in the same upright direction to illustrate their identical construction.

In carrying out my invention as herein embodied H1 and I I represent two identical members produced from suitable insulating material and of any appropriate size to accommodate various sizes of conductors, wires or cables.

Each member H), H is comprised of a semicylindrical body l2 having a longitudinal channel 13 in the inner face with longitudinal contact edges M on opposite sides of said channel. In the body of each member, adjacent one end thereof is formed an internal recess or bay I5 which is semi-elliptical in cross section and is in communication with the channel. To provide the semi-elliptical formation of the recess or bay I5 the mouth thereof is the same width as the channel while the main portion of said recess extends back, in elongated fashion, into the body towards the outer rear surface of the latter. This formation produces crescent shaped gripping shoulders 16, Figs. 2 and 3, for firmly gripping portions of the conductor, wire or cable as the same is forced into the recess or bay l5.

With the member body is also formed a transversely extending internal rib l1 within the channel [3 adjacent the end of said body opposite the location of the recess or bay I5. The rib is approximately the same distance from alocation midway between the ends of the body,v towards one end,.as is the recess or bay 15 towards the opposite end of said body and said rib protrudes a short distance into the channel from arcuate surface thereof.

On one end of the member body is formed an indicating means l8,.such as a lug, to differentiate one end from the other of the member which indicating means is highly advantageous during assembly of the wire strain reliever as will become apparent from the description below.

Midway between the ends of the member body is formed an external groove l9 which is semielliptical in cross section of the body, being deepest-at the extreme back of said body and the bottom surface of said groove finally merging with the exterior surface of the body or the ends of said groove run out at the sides of the member.

As previously stated the wire strain reliever of the present invention consists of two identical members and in assembling the device on a conductor, wire or cable, shown in dotted lines in Fig. 1 and designated by the numeral 20, one member is inverted and placed in reverse cooperative relation to the other or companion member. The proper positioning of the members is assisted by the indicating means 18 through either the sense of touch or sight, a user knowing in advance that the indicating means on companion members must be at opposite ends of the assembled article.

After being properly positioned on the electrical conductor a suitable tool may be employed to grip one end of the device at right angles to the joint between the members and the latter forced towards one another and against the conductor. This will form two oppositely projecting bends or kinks in the conductor as shown in Fig. 1. The wire strain reliever, with the conductor so assembled, is then mounted in an opening 2! in a mounting member 22, panel, wall or the like with the elliptical groove, formed by the cooperating semi-elliptical grooves of the two members, seated on the marginal portions of said opening 2|.

Because of the resiliency of the covering of the conductor wire, the two members tend to separate, when the tool is disengaged therefrom, and thus secure the assembly in firm holding relation to the mounting member and the conductor cannot be pulled lengthwise under ordinary conditions.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the appended claims without departing from the spirit of my invention.

Having described my invention what I claim as new and useful is:

1. In a device of the kind described, a pair of identical members in reverse and inverted rela body, said body further having a recess adjacent one end extending into the body material from the channel with which said recess communicates, a rib projecting into said channel adjacent the opposite nd of the body, the rib of one memher being directly opposite the recess of the other member when the companion members are in juxtaposed relation with their respective contact edges in confronting relation whereby the channels, recesses and ribs define a circuitous conductor receiving passage, and means to retain the assembled device on a conductor and within an aperture in a mounting member.

2. In a device of the kind described, a pair of identical members in reverse and inverted relation collectively defining a wire strain reliever, each member'produced from insulating material and comprising a semi-cylindricalbody providing a longitudinal channel and including contact edges extending the entire length of the body, said body further having a semi-elliptical recess adjacent one end extending into the body material from the channel with which said recess communicates, a transverse rib projecting from the body material adjacent the end opposite the recess a short distance into said channel, and an 4 exterior groove in the outer convex surface of the body midway the length of said body, the groove being so fashioned that when the companion members are in juxtaposed relation with their respective contact edges in confronting relation the grooves form a strain reliever retaining groove to be seated on the marginal edge of a hole in a mounting member and the rib of one member is directly opposite the recess of the companion member whereby said channels, recesses and ribs define a circuitous conductor receiving passage.

' 3. The structure according to claim 2 wherein the complete retaining groove is elliptical when considered with relation to a cross section of the strain reliever.

4. The structure according to claim 2, in combination with indicating means on the same ends of the respective members which indicating means will be at opposite ends of the assembled strain reliever.

5. The structure according to claim 4 wherein the indicating means is an integral lug projecting from the end surface of its respective -member.

6. A wire strain reliever comprised of two identical members each consisting of a semi-cylindrical body providing a longitudinal channel and contact edge surfaces at the sides of the channel, said body further having a recess adjacent one end communicating with the channel and also provided with an exterior semi-elliptical groove intermediate the ends of said body, said groove being deepest at the back of the member body and gradually becoming shallower until it runs out at the side edges of said body, a transverse rib projecting a short distance into the channel adjacent the other end of the body, and an indicating lug projecting from an end of said body, said members being positioned in reverse inverted relation with the indicating lugs at opposite ends of the assembled device whereby a conductor receiving passage is formed with the rib of each member directly opposite the recess of the companion member to produce oppositely projecting bends at spaced locations in a conductor within the passage and the semi-elliptical grooves forming a completely surrounding retaining groove having long and short diameters with the long diameter across the meeting edges of the member.

7. In a device of the kind described, a pair of identical members in reverse and inverted relanel and opposed to a recess in the companion member whereby the cooperating recesses and snubbing shoulders forma circuitous passageway when said members are in the aforesaid inverted and juxtaposed relation.

References Cited in the file of this patent UNITED STATES PATENTS Number Na 

